Electromagnetic driver



Ju e 15 ,1926.

W. H. GERNS ELECTROMAGNETIC DRIVER Filed Nov. 28 1925 FIG 2 FIG FIGG

FIG '5 WILLIAM H. GEE/IS INVENTOR.

ATTORNEY Patented June 15, 1926.

UNITED STATES rarsn'r QFFEQEQ WILLIAM H. GERNS, OF EAST ORANGE, NEW JERfiEY, ASSIGNOR T BRANIJES LABORA- TORIES, INC.,- QF NEWARK, NEW JERSEY, A CORPORATION Oi INEW JERSEY.

ELECTROMAGNETIC Dawns.

Application filed November 2a, was. Serial No. risen.

My invention relates broadly to the reproduction of sound from electrical vibrations and more particularly to the construction of an electromagnetic driver for sound re- 6 producers.

One of the objects of my invention is to provide=an electromagnetic driver for sound rcproducers which is capable of developing vibrations of relatively large amplitude from electrical vibrations by reason of an opposed relationship of a pair of electromagnetic systems arranged to operate upon the same armature.

Another object of my invention is to provide a construction of armature for an electromagnetic driver of the double magnetic type where the armature provides means for positively spacing the electromagnetic systems one from another and has the necessary resiliencyimparted thereto by reason of its characteristic-shape with means for taking off the mechanical vibrations from v the armature for driving a sound reproducinn; diaphragm.

- Still anothe object of my invention is to provide a construction of armature for a double magnetic type of electromagnetic 7 sound reproducer, in which the armature formed from a flat plate of magnetic mate rial armatured in the shape of plurality of sectors vand a semi-circle for imparting a desired degree of resiliency to the armature and providing a proper distribution of magnetic lines therethrough.

A further object of my invention is to provide a construction of armature. for a double magnetic construction of electromagnetic driver, in which the armature may be stamped from a fiat sheet of magnetic material with a diametrica-l bridge member, which is subjected to the vibratory action of the electromagnetic system and a radial portion of which is shaped to provide means for deliver-inflthe vibrations thus produced upon a sound reproducing diaphragm.

My invention will be more clearly understood by reference to the following specification and the accompanying drawings, in svhichz Figure 1 is an end view, showing the arrangement of parts of the electromagnetic driver; Fi 2 is a cross-sectional view taken throu h tile double magnetic electromagnetie river; Fig. 3 is a cross-sectional view through the driver taken on line 3-3of Fig.

is aligned with an oppositelypositioned casmg 2 of an electromagnetic sound reproducer secured together by means of bolt members 3. Permanent magnets 4 and 5 are mounted adjacent each of the casings l and 2 and have sets of pole pieces 6 and 7 secured thereto. The pole pieces 6 and 7 are provided with electromagnetic windings 8 and 9. by which magnetic forces are imparted to thearinature 10. Alternate attractive and repulsive forces may-be applied to the armature 10, thereby increasing the amplitude of movement of the armature and correspondingly the volume of the reproduced sound. The armature construction forms the particular feature of my invention. The armature is punched from a fiat sheet of magnetic material in such manner asv to provide apertures 3% adjacent the circum-, l ercncc thereof, by which the armature is maintained in position by bolt members 3 and serves as a and 2. The armature 10 is apertured i a plurality of segments, represented at 11 and 12 and in a semi-circular portion. rep're sented at "14. The segments 11 and 12 are substantially quadrant and are positioned on opposite sides of a radial bridge-like portion 15. The segmental apertures 11 and 12 lie "adjacent the semi-circular aperture 14 on opposite sides of the diametrical portion 16., which forms the principal area. which is sni jected tothc magnetic lines of force emanating from pole pieces 8 and '2. The bridge. like member 15 is pressed in such manner that side portions 17 and 18 extendupward- -l'y therefrom in the form of achanneh as spacing means for casings l i portions 17 and 18 may be bent onlypartially into a circular s ape, leaving a gap 22 b' tweenadjacent ends of the side portions 17 and 18. The shape being such,'however,

tions may be impressed upon a sound reproducing diaphragm with a high degree of efficiency. The construction of the armature in the manner illustrated facilitates manufacture reproducer.

ator in a cone speaker, where the rod member 21 connects with theapex of a conical diaphragm and positively moves the cone in opposite directions, by virtue of the attraction and repulsion offered by electromagnetic system.

\Vhile I have illustrated the armature construction in certain preferred embodiforces of said ments, I desire that.it be understood that modifications may be made and that no limitations upon the invention are intended other than are imposed by the scope ofthe appended claims. \Vhat I claim and desire to secure by" Letters Patent of the UnitedStat es is as follows:- v

1. In an electromagnetic driver, a sound reproducing diaphragm, a pair of electromagnetic driving units positioned oppos te each other, an armature positioned between said electromagnetic driving units, said armaturecomprising a Hat sheet of magnetic material apertured in a plurality of segments, one of which circular, .a band extending between each of said segments, one of said bands being d rectly actuated by attractive and repulsive electromagnetic driving units andthe other of said bands being arranged to deliver mechanical vibrations from said armature to said sound reproducing diaphragm.

2. In an electromagnetic sound reproducer, the combination of a pair of independent electromagnetic rlrivers each having pole pieces directed toward each other,

a sound reproducing diaphragm, a circular armature member positioned between said drivers, and having a diametrically extending'band across the center thereof arranged to be actuated by attractive and repulsive- )rces from said pole pieces, and a bridgemember disposed between said band, and one side of said circular armature member, e'lwrebv mechanical forces set up in said 21 on the bridge member 15 is such that mechanical v braof the electromagnetic sound The electromagnetic dr ving unit lends itself particularly well as an actu the double is substantially semitending radially ing pole pieces directed toward each other, 7

,a sound reproducing diapl'iragm, a circular arn'iatnre member positioned between said drivers, said circulararmature member comprising a: flat sheet-of magnetic vmaterial apertured in a plurality of segments, with each of said segments separated by bands of relatively different widths, said armature member being arranged to receive mechanical vibrations along' one of saidbands and transfer mechanical vibrations to said sound reproducing diaphragm along another band. I i r 4, in. an electroi'nagnetic soundreproducer, the combination of a pair of independentelectromagnetic drivers each having pole pieoes directed toward each other, a sound reprbducing diaphragm, a circular armature member positioned between said drivers, said circular armature member being npertured to form a )air of band members directed at right ang es to each other, with one of said band members extending diametrically across said circular armature member and the other of saidband members extending radially across said circular armature member from said first-mentioned band member, whereby re ulsive and attractive forces set up in said first mentioned band member may be conveyed to said second mentioned band member for actuating said sound reproducing ,diaphragm.

in an electromagi'ietic sound reproducer, the combination of a pair of inde pendent electromagnetic drivers each having pole pieces directed toward each other, a sound reproducing diaphragm, a circular armatnre'member positioned between said drivers, said circular armature member being apertui-ed in three segmental parts, forming a narrow band and a relatively wide band therehetween, with the relatively wide band extending diametrically ofsaid armature and the relatively narrow band ex? I 'i said armature between said relatively wide band and the outer periphery of said circular armature mem-;

her, whereby mechanical. forces set up in ing apertured in a plurality of segmental shapes, with a relatively Wide band extendnel shaped in cross-section, and meansconnccted between said channel shaped relatively narrow band and said sound reproducing diaphragm, whereby mechanical vibrations set up in said" relatively wide band are transferred-to said sound reproduc ing diaphragm through said relatively narrow band. a

7. In an electromagnetic sound reproducer, the combination of a pair of inde pendent electromagnetic drivers each havmg pole pieces directed toward each other,-

a sound reproducing diaphragm, a circular armature member positioned between said drivers, said circular armature member being formed into a pair of integral band portions, one disposed at right angles to the other, one of said band members being actuated by said electromagnetic drivers, and the other of said band members being mechanically vibrated from said first mentioned band member. 7

8. In an electromagnetic sound roproducer, the coinbinationcf a pair ofindependent electromagnetic drivers each having pole pieces directed toward each other, a sound reproducing diaphragm, a circaiar armature member positioned between said drivers,-said circular armature member having a pair of strip like portions disposed at right angles to-cach other, one of said strip like portions being actuated by said electromagnetic drivers, and the other of said strip like portions being arranged to impart mechanical vibrations to said sound'freproducing diaphragm.

WILLIAM H. GERNS. 

